KR102593441B1 - Transmitter using symbol constellation rotation and spectrum shaping in communication system, transmitting method thereof, receiver using the same, and receiving method thereof - Google Patents

Transmitter using symbol constellation rotation and spectrum shaping in communication system, transmitting method thereof, receiver using the same, and receiving method thereof Download PDF

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KR102593441B1
KR102593441B1 KR1020210116620A KR20210116620A KR102593441B1 KR 102593441 B1 KR102593441 B1 KR 102593441B1 KR 1020210116620 A KR1020210116620 A KR 1020210116620A KR 20210116620 A KR20210116620 A KR 20210116620A KR 102593441 B1 KR102593441 B1 KR 102593441B1
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조준호
최정훈
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/3405—Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power
    • H04L27/3444—Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power by applying a certain rotation to regular constellations
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03828—Arrangements for spectral shaping; Arrangements for providing signals with specified spectral properties
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/38—Synchronous or start-stop systems, e.g. for Baudot code
    • H04L25/40—Transmitting circuits; Receiving circuits
    • H04L25/49—Transmitting circuits; Receiving circuits using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems
    • H04L25/4917—Transmitting circuits; Receiving circuits using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems using multilevel codes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/0008—Modulated-carrier systems arrangements for allowing a transmitter or receiver to use more than one type of modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2614—Peak power aspects
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2614—Peak power aspects
    • H04L27/2621—Reduction thereof using phase offsets between subcarriers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2626—Arrangements specific to the transmitter only
    • H04L27/2627—Modulators
    • H04L27/2634—Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation
    • H04L27/2636—Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation with FFT or DFT modulators, e.g. standard single-carrier frequency-division multiple access [SC-FDMA] transmitter or DFT spread orthogonal frequency division multiplexing [DFT-SOFDM]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
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    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2649—Demodulators
    • H04L27/26524—Fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators in combination with other circuits for demodulation
    • H04L27/26526—Fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators in combination with other circuits for demodulation with inverse FFT [IFFT] or inverse DFT [IDFT] demodulators, e.g. standard single-carrier frequency-division multiple access [SC-FDMA] receiver or DFT spread orthogonal frequency division multiplexing [DFT-SOFDM]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/3405—Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power
    • H04L27/3411—Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power reducing the peak to average power ratio or the mean power of the constellation; Arrangements for increasing the shape gain of a signal set
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/0001—Arrangements for dividing the transmission path
    • H04L5/0003—Two-dimensional division
    • H04L5/0005—Time-frequency
    • H04L5/0007—Time-frequency the frequencies being orthogonal, e.g. OFDM(A) or DMT
    • H04L5/001—Time-frequency the frequencies being orthogonal, e.g. OFDM(A) or DMT the frequencies being arranged in component carriers

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Abstract

심볼 간 간섭이 없으면서도 PAPR과 주파수 효율을 손쉽게 트레이드 오프할 수 있도록 성상 회전각 및 주파수 영역 스펙트럼 성형벡터가 설계된, M개의 PAM 심볼을 포함하는 심볼벡터를 성상 회전각만큼 성상 회전시켜 성상 회전된 심볼벡터를 생성하는 성상 회전부와, pruned DFT 행렬을 이용하여 상기 성상 회전된 심볼벡터를 확산시켜 pruned DFT 확산된 벡터를 생성하는 pruned DFT 확산부와, 상기 pruned DFT 확산된 벡터에 성형벡터를 하다마드 곱함으로써 주파수 영역 스펙트럼 성형된 벡터를 생성하는 주파수 영역 스펙트럼 성형부와, 상기 주파수 영역 스펙트럼 성형된 벡터를 할당된 주파수 범위의 부반송파에 할당하는 부반송파 할당부를 포함하는 DFT-spread OFDM 송신기, 송신 방법, 및 이에 의한 신호를 수신할 수 있는 DFT-spread OFDM 수신기 및 수신 방법을 제공한다.The constellation rotation angle and frequency domain spectrum shaping vector are designed to easily trade-off PAPR and frequency efficiency without interference between symbols. A symbol vector containing M PAM symbols is rotated by the constellation rotation angle to create a constellation rotated symbol. A constellation rotation unit that generates a vector, a pruned DFT diffusion unit that spreads the constellation rotated symbol vector using a pruned DFT matrix to generate a pruned DFT spread vector, and a shaping vector is multiplied by the pruned DFT spread vector. A DFT-spread OFDM transmitter, a transmission method, and the same, including a frequency-domain spectrum shaping unit that generates a frequency-domain spectrum-shaped vector, and a subcarrier allocation unit that allocates the frequency-domain spectrum-shaped vector to a subcarrier in an assigned frequency range. Provides a DFT-spread OFDM receiver and reception method that can receive signals from

Figure R1020210116620
Figure R1020210116620

Description

통신 시스템에서 심볼 성상 회전 및 스펙트럼 성형을 이용한 송신기, 이의 송신 방법, 수신기 및 이의 수신 방법{TRANSMITTER USING SYMBOL CONSTELLATION ROTATION AND SPECTRUM SHAPING IN COMMUNICATION SYSTEM, TRANSMITTING METHOD THEREOF, RECEIVER USING THE SAME, AND RECEIVING METHOD THEREOF}Transmitter using symbol constellation rotation and spectrum shaping in a communication system, a transmission method thereof, a receiver, and a reception method thereof

본 발명은 통신 시스템에서 성상 회전각 및 스펙트럼 성형을 이용한 신호 송신 및 수신에 관한 것이다.The present invention relates to signal transmission and reception using constellation rotation angle and spectrum shaping in a communication system.

4G 이동통신에서는 상향 링크에서 낮은 첨두 대 평균 전력비(PAPR: peak-to-average power ratio)를 얻기 위해 localized SC-FDMA(single-carrier frequency domain multiple access)의 일종인 이산푸리에변환(DFT: discrete Fourier transform)-확산(spread) 직교주파수분할다중화(OFDM: orthogonal frequency-division multiplexing)가 채택되었다. 낮은 PAPR 성능은 사용자 장치(user equipment)의 전력 증폭기(power amplifier) 효율을 증가시켜 보다 넓은 셀 커버리지를 제공한다.In 4G mobile communications, discrete Fourier transform (DFT), a type of localized single-carrier frequency domain multiple access (SC-FDMA), is used to obtain a low peak-to-average power ratio (PAPR) in the uplink. transform-spread orthogonal frequency-division multiplexing (OFDM) was adopted. Low PAPR performance increases the power amplifier efficiency of user equipment, providing wider cell coverage.

5G 이동통신에서도 상향 링크에 직교주파수분할다중접속(OFDMA: orthogonal frequency division multiple access)뿐만 아니라 낮은 PAPR 성능을 위해 종래의 DFT-spread OFDM을 채택하였다. 특히, 4G 이동통신에 비해 5G 이동통신에서 채택된 DFT-spread OFDM은 PAPR 성능을 더욱 개선하기 위해 pi/2-BPSK(binary phase shift keying) 심볼과 주파수 영역 스펙트럼 성형을 지원한다.In 5G mobile communication, conventional DFT-spread OFDM was adopted for low PAPR performance as well as orthogonal frequency division multiple access (OFDMA) in the uplink. In particular, DFT-spread OFDM adopted in 5G mobile communication compared to 4G mobile communication supports pi/2-BPSK (binary phase shift keying) symbol and frequency domain spectrum shaping to further improve PAPR performance.

그러나 pi/2-BPSK 심볼의 사용은 종래의 QPSK 심볼에 비해 주파수 효율이 절반이 되며, 결과적으로 PAPR의 성능 개선은 주파수 효율의 희생으로 얻어진다. 즉, PAPR과 주파수 효율은 일반적으로 트레이드-오프(trade-off)의 관계를 가지는데, 5G 이동통신에서는 pi/2-BPSK와 QPSK 사이의 주파수 효율값을 제공하지 못하고 있다. 따라서 PAPR과 주파수 효율을 적절히 트레이드-오프할 수 있는 송수신 방법이 필요하다.However, the use of the pi/2-BPSK symbol reduces the frequency efficiency by half compared to the conventional QPSK symbol, and as a result, the performance improvement of PAPR is achieved at the expense of frequency efficiency. In other words, PAPR and frequency efficiency generally have a trade-off relationship, but 5G mobile communication does not provide frequency efficiency values between pi/2-BPSK and QPSK. Therefore, a transmission and reception method that can appropriately trade-off PAPR and frequency efficiency is needed.

한국 공개특허공보 제10-2011-0076316호(2011.07.06.)Korean Patent Publication No. 10-2011-0076316 (2011.07.06.)

본 발명의 목적은 심볼 간 간섭이 없으면서도 PAPR과 주파수 효율을 손쉽게 트레이드 오프할 수 있도록 성상 회전각 및 주파수 영역 스펙트럼 성형벡터를 설계 한 DFT-spread OFDM 송신기, 송신 방법, 및 이에 의한 신호를 수신할 수 있는 DFT-spread OFDM 수신기 및 수신 방법을 제공하는 것이다.The purpose of the present invention is to design a DFT-spread OFDM transmitter with a constellation rotation angle and frequency domain spectrum shaping vector so that PAPR and frequency efficiency can be easily traded off without inter-symbol interference, a transmission method, and a method for receiving signals thereby. To provide a DFT-spread OFDM receiver and reception method that can

다만, 본 발명의 해결하고자 하는 과제는 이에 한정되는 것이 아니며, 본 발명의 사상 및 영역으로부터 벗어나지 않는 범위에서 다양하게 확장될 수 있을 것이다.However, the problem to be solved by the present invention is not limited to this, and may be expanded in various ways without departing from the spirit and scope of the present invention.

본 발명의 일 실시예에 따른 이산푸리에변환(DFT: discrete Fourier transform)-확산(spread) 직교주파수분할다중화(OFDM: orthogonal frequency-division multiplexing) 송신기는, M개의 PAM(pulse amplitude modulation) 심볼을 포함하는 심볼벡터(

Figure 112021101498369-pat00001
)를 성상 회전각(
Figure 112021101498369-pat00002
)만큼 성상 회전시켜 성상 회전된 심볼벡터(
Figure 112021101498369-pat00003
)를 생성하는 성상 회전부와, pruned DFT 행렬(
Figure 112021101498369-pat00004
)을 이용하여 상기 성상 회전된 심볼벡터(
Figure 112021101498369-pat00005
)를 확산시켜 pruned DFT 확산된 벡터(
Figure 112021101498369-pat00006
)를 생성하는 pruned DFT 확산부와, 상기 pruned DFT 확산된 벡터(
Figure 112021101498369-pat00007
)에 성형벡터(
Figure 112021101498369-pat00008
)를 하다마드 곱(Hadamard product)함으로써 주파수 영역 스펙트럼 성형된 벡터(
Figure 112021101498369-pat00009
)를 생성하는 주파수 영역 스펙트럼 성형부와, 상기 주파수 영역 스펙트럼 성형된 벡터(
Figure 112021101498369-pat00010
)를 할당된 주파수 범위의 부반송파에 할당하는 부반송파 할당부를 포함한다.A discrete Fourier transform (DFT)-spread orthogonal frequency-division multiplexing (OFDM) transmitter according to an embodiment of the present invention includes M pulse amplitude modulation (PAM) symbols. The symbol vector (
Figure 112021101498369-pat00001
) as the rotation angle (
Figure 112021101498369-pat00002
) by rotating the constellation and creating the rotated symbol vector (
Figure 112021101498369-pat00003
) and a pruned DFT matrix (
Figure 112021101498369-pat00004
) using the constellation rotated symbol vector (
Figure 112021101498369-pat00005
) by spreading the pruned DFT spread vector (
Figure 112021101498369-pat00006
) and the pruned DFT spread vector (
Figure 112021101498369-pat00007
) to the forming vector (
Figure 112021101498369-pat00008
) by the Hadamard product to obtain a frequency domain spectrum shaped vector (
Figure 112021101498369-pat00009
), a frequency domain spectrum shaping unit that generates a frequency domain spectrum shaping vector (
Figure 112021101498369-pat00010
) includes a subcarrier allocation unit that allocates subcarriers in the allocated frequency range.

일 측면에 따르면, M이 짝수인 경우, 상기 성상 회전각(

Figure 112021101498369-pat00011
)은 하기의 수학식According to one aspect, when M is an even number, the constellation rotation angle (
Figure 112021101498369-pat00011
) is the equation below:

에 의해 결정 - 여기서, L은 사용될 부반송파의 개수임 - 될 수 있다.It can be determined by - where L is the number of subcarriers to be used.

일 측면에 따르면, M이 홀수인 경우, 상기 성상 회전각(

Figure 112021101498369-pat00013
)은 하기의 수학식According to one aspect, when M is an odd number, the constellation rotation angle (
Figure 112021101498369-pat00013
) is the equation below:

에 의해 결정 - 여기서, L은 사용될 부반송파의 개수임 - 될 수 있다.It can be determined by - where L is the number of subcarriers to be used.

일 측면에 따르면, 상기 pruned DFT 행렬(

Figure 112021101498369-pat00015
)의 (i, j) 성분은 하기의 수학식According to one aspect, the pruned DFT matrix (
Figure 112021101498369-pat00015
) The (i, j) components of ) are expressed in the following equation:

에 의해 결정 - 여기서, 인덱스 i, j는 각각 1≤i≤L, 1≤j≤M 을 만족함 - 될 수 있다.- Here, the indices i and j satisfy 1≤i≤L and 1≤j≤M, respectively.

일 측면에 따르면, M이 짝수인 경우, 상기 성형벡터(

Figure 112021101498369-pat00017
)의 l번째 성분은 하기의 수학식According to one aspect, when M is an even number, the shaping vector (
Figure 112021101498369-pat00017
)'s lth component is the equation below:

에 의해 결정 - 여기서, l = 0, 1, 2, …, L-1 이고, M/2≤L≤M 임 - 될 수 있다.Determined by - where l = 0, 1, 2, … , L-1, and M/2≤L≤M - can be.

일 측면에 따르면, M이 홀수인 경우, 상기 성형벡터(

Figure 112021101498369-pat00019
)의 l번째 성분은 하기의 수학식According to one aspect, when M is an odd number, the shaping vector (
Figure 112021101498369-pat00019
)'s lth component is the equation below:

에 의해 결정 - 여기서, l = 0, 1, 2, …, L-1 이고, M/2≤L≤M 임 - 될 수 있다.Determined by - where l = 0, 1, 2, … , L-1, and M/2≤L≤M - can be.

일 측면에 따르면, 상기 DFT-spread OFDM 송신기는 상기 부반송파할당부의 출력에 대하여 N-포인트 IDFT(N-point inverse discrete Fourier transform)를 수행하고 순환전치(CP: cyclic prefix)를 삽입함으로써 신호(

Figure 112021101498369-pat00021
)를 생성하는 OFDM신호생성부를 더 포함할 수 있다.According to one aspect, the DFT-spread OFDM transmitter performs N-point inverse discrete Fourier transform (IDFT) on the output of the subcarrier allocation unit and inserts a cyclic prefix (CP) to signal (
Figure 112021101498369-pat00021
) may further include an OFDM signal generator that generates.

본 발명의 일 실시예에 따른 이산푸리에변환(DFT: discrete Fourier transform)-확산(spread) 직교주파수분할다중화(OFDM: orthogonal frequency-division multiplexing) 송신기에 의해 수행되는 DFT-spread OFDM 송신 방법은, M개의 PAM(pulse amplitude modulation) 심볼을 포함하는 심볼벡터(

Figure 112021101498369-pat00022
)를 성상 회전각(
Figure 112021101498369-pat00023
)만큼 성상 회전시켜 성상 회전된 심볼벡터(
Figure 112021101498369-pat00024
)를 생성하는 단계와, pruned DFT 행렬(
Figure 112021101498369-pat00025
)을 이용하여 상기 성상 회전된 심볼벡터(
Figure 112021101498369-pat00026
)를 확산시켜 pruned DFT 확산된 벡터(
Figure 112021101498369-pat00027
)를 생성하는 단계와, 상기 pruned DFT 확산된 벡터(
Figure 112021101498369-pat00028
)에 성형벡터(
Figure 112021101498369-pat00029
)를 하다마드 곱(Hadamard product)함으로써 주파수 영역 스펙트럼 성형된 벡터(
Figure 112021101498369-pat00030
)를 생성하는 단계와, 상기 주파수 영역 스펙트럼 성형된 벡터(
Figure 112021101498369-pat00031
)를 할당된 주파수 범위의 부반송파에 할당하는 단계를 포함한다.The DFT-spread OFDM transmission method performed by a discrete Fourier transform (DFT)-spread orthogonal frequency-division multiplexing (OFDM) transmitter according to an embodiment of the present invention is, M A symbol vector containing PAM (pulse amplitude modulation) symbols (
Figure 112021101498369-pat00022
) as the rotation angle (
Figure 112021101498369-pat00023
) by rotating the constellation and creating the rotated symbol vector (
Figure 112021101498369-pat00024
), and the pruned DFT matrix (
Figure 112021101498369-pat00025
) using the constellation rotated symbol vector (
Figure 112021101498369-pat00026
) by spreading the pruned DFT spread vector (
Figure 112021101498369-pat00027
), and the pruned DFT spread vector (
Figure 112021101498369-pat00028
) to the forming vector (
Figure 112021101498369-pat00029
) by the Hadamard product to obtain a frequency domain spectrum shaped vector (
Figure 112021101498369-pat00030
), generating the frequency domain spectrum shaped vector (
Figure 112021101498369-pat00031
) to a subcarrier in the assigned frequency range.

본 발명의 일 실시예에 따른 이산푸리에변환(DFT: discrete Fourier transform)-확산(spread) 직교주파수분할다중화(OFDM: orthogonal frequency-division multiplexing) 수신기는, 채널을 통과한 신호(

Figure 112021101498369-pat00032
)를 수신하고, 상기 신호(
Figure 112021101498369-pat00033
)로부터 순환 전치(CP: cyclic prefix)를 제거함으로써 순환 전치가 제거된 벡터(
Figure 112021101498369-pat00034
)를 생성하는 순환 전치 제거부와, 상기 순환 전치가 제거된 벡터(
Figure 112021101498369-pat00035
)에 N-포인트 DFT(N-point discrete Fourier transform)를 수행한 후 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 벡터(
Figure 112021101498369-pat00036
)를 생성하는 N-포인트 DFT 부와, 상기 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 벡터(
Figure 112021101498369-pat00037
)에 수신 성형벡터(
Figure 112021101498369-pat00038
)의 켤레 복소 벡터를 하다마드 곱함으로써 주파수 영역 수신 스펙트럼 성형된 벡터를 생성하는 주파수 영역 수신 스펙트럼 성형부와, 상기 주파수 영역 수신 스펙트럼 성형된 벡터에 전치된 pruned DFT 행렬(
Figure 112021101498369-pat00039
)을 곱함으로써 역확산된 벡터를 생성하는 pruned IDFT부와, 상기 역확산된 벡터를 역성상 회전각(
Figure 112021101498369-pat00040
)만큼 역성상 회전시켜 역성상 회전된 벡터를 생성하는 역성상회전부와, 상기 역성상 회전된 벡터의 실수부를 취함으로써 전송된 PAM(pulse amplitude modulation) 심볼 벡터의 추정값(
Figure 112021101498369-pat00041
)을 생성하는 추정부를 포함한다.A discrete Fourier transform (DFT)-spread orthogonal frequency-division multiplexing (OFDM) receiver according to an embodiment of the present invention provides a signal that has passed through the channel (
Figure 112021101498369-pat00032
), and receives the signal (
Figure 112021101498369-pat00033
) by removing the cyclic prefix (CP) from the vector (
Figure 112021101498369-pat00034
) and a cyclic prefix removal unit that generates a vector (
Figure 112021101498369-pat00035
) after performing N-point DFT (N-point discrete Fourier transform) on the vector (
Figure 112021101498369-pat00036
) and a vector (
Figure 112021101498369-pat00037
) to the receiving shaping vector (
Figure 112021101498369-pat00038
a frequency domain received spectrum shaping unit that generates a frequency domain received spectrum shaped vector by multiplying the complex conjugate vector of ) by Hadamard, and a pruned DFT matrix transposed to the frequency domain received spectrum shaped vector (
Figure 112021101498369-pat00039
) and a pruned IDFT unit that generates a despread vector by multiplying the despread vector by an inverse constellation rotation angle (
Figure 112021101498369-pat00040
), an inverse constellation rotation unit that rotates the inverse constellation to generate an inverse constellation rotated vector, and an estimate of the transmitted PAM (pulse amplitude modulation) symbol vector by taking the real part of the inverse constellation rotated vector (
Figure 112021101498369-pat00041
) includes an estimation unit that generates.

일 측면에 따르면, 상기 채널이 주파수 비선택적(frequency flat)인 경우, 상기 수신 성형벡터는 송신 성형벡터와 동일할 수 있다.According to one aspect, when the channel is frequency non-selective (frequency flat), the reception shaping vector may be the same as the transmission shaping vector.

본 발명의 일 실시예에 따른 이산푸리에변환(DFT: discrete Fourier transform)-확산(spread) 직교주파수분할다중화(OFDM: orthogonal frequency-division multiplexing) 수신기에 의해 수행되는 DFT-spread OFDM 수신 방법은, 채널을 통과한 신호(

Figure 112021101498369-pat00042
)를 수신하고, 상기 신호(
Figure 112021101498369-pat00043
)로부터 순환 전치(CP: cyclic prefix)를 제거함으로써 순환 전치가 제거된 벡터(
Figure 112021101498369-pat00044
)를 생성하는 단계와, 상기 순환 전치가 제거된 벡터(
Figure 112021101498369-pat00045
)에 N-포인트 DFT(N-point discrete Fourier transform)를 수행한 후 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 벡터(
Figure 112021101498369-pat00046
)를 생성하는 단계와, 상기 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 벡터(
Figure 112021101498369-pat00047
)에 수신 성형벡터(
Figure 112021101498369-pat00048
)의 켤레 복소 벡터를 하다마드 곱함으로써 주파수 영역 수신 스펙트럼 성형된 벡터를 생성하는 단계와, 상기 주파수 영역 수신 스펙트럼 성형된 벡터에 전치된 pruned DFT 행렬(
Figure 112021101498369-pat00049
)을 곱함으로써 역확산된 벡터를 생성하는 단계와, 상기 역확산된 벡터를 역성상 회전각(
Figure 112021101498369-pat00050
)만큼 역성상 회전시켜 역성상 회전된 벡터를 생성하는 단계와, 상기 역성상 회전된 벡터의 실수부를 취함으로써 전송된 PAM(pulse amplitude modulation) 심볼 벡터의 추정값(
Figure 112021101498369-pat00051
)을 생성하는 단계를 포함한다.The DFT-spread OFDM reception method performed by a discrete Fourier transform (DFT)-spread orthogonal frequency-division multiplexing (OFDM) receiver according to an embodiment of the present invention includes a channel The signal that passed through (
Figure 112021101498369-pat00042
), and receives the signal (
Figure 112021101498369-pat00043
) by removing the cyclic prefix (CP) from the vector (
Figure 112021101498369-pat00044
), and a vector from which the cyclic transpose is removed (
Figure 112021101498369-pat00045
) after performing N-point DFT (N-point discrete Fourier transform) on the vector (
Figure 112021101498369-pat00046
), and a vector (
Figure 112021101498369-pat00047
) to the receiving shaping vector (
Figure 112021101498369-pat00048
generating a frequency domain received spectrum shaped vector by Hadamard multiplying the complex conjugate vector of ), and a pruned DFT matrix transposed to the frequency domain received spectrum shaped vector (
Figure 112021101498369-pat00049
), generating a despread vector by multiplying the despread vector by an inverse constellation rotation angle (
Figure 112021101498369-pat00050
A step of generating an inverse constellation rotated vector by inverse constellation rotation, and an estimate of the transmitted PAM (pulse amplitude modulation) symbol vector by taking the real part of the inverse constellation rotated vector (
Figure 112021101498369-pat00051
) includes the step of generating.

개시된 기술은 다음의 효과를 가질 수 있다. 다만, 특정 실시예가 다음의 효과를 전부 포함하여야 한다거나 다음의 효과만을 포함하여야 한다는 의미는 아니므로, 개시된 기술의 권리범위는 이에 의하여 제한되는 것으로 이해되어서는 아니 될 것이다.The disclosed technology can have the following effects. However, since it does not mean that a specific embodiment must include all of the following effects or only the following effects, the scope of rights of the disclosed technology should not be understood as being limited thereby.

전술한 본 발명의 실시예들에 따른 DFT-spread OFDM 송신기, 송신 방법, 및 이에 의한 신호를 수신할 수 있는 DFT-spread OFDM 수신기 및 수신 방법에 따르면, 심볼 간 간섭이 없으면서도 PAPR과 주파수 효율을 손쉽게 트레이드 오프할 수 있도록 성상 회전각 및 주파수 영역 스펙트럼 성형벡터를 설계할 수 있다.According to the DFT-spread OFDM transmitter, transmission method, and DFT-spread OFDM receiver and reception method capable of receiving signals thereby according to the embodiments of the present invention described above, PAPR and frequency efficiency are maintained without inter-symbol interference. Constellation rotation angle and frequency domain spectral shaping vectors can be designed to allow for easy trade-off.

도 1은 본 발명의 일 실시예에 따른 DFT-spread OFDM 송신기의 구성을 나타낸 블록도이다.
도 2는 도 1의 성상 회전부를 상세하게 나타낸 블록도이다.
도 3은 도 1의 pruned DFT 확산부를 상세하게 나타낸 블록도이다.
도 4는 도 1의 주파수 영역 스펙트럼 성형부를 상세하게 블록도이다.
도 5는 본 발명의 일 실시예에 따른 DFT-spread OFDM 송신 방법의 순서도이다.
도 6은 본 발명의 일 실시예에 따른 DFT-spread OFDM 수신기의 구성을 나타낸 블록도이다.
도 7은 본 발명의 일 실시예에 따른 DFT-spread OFDM 수신 방법의 순서도이다.
도 8은 고정된 부반송파수에서 송신된 BPSK 심볼 개수에 따른 주파수 효율을 나타낸 그래프이다.
도 9는 고정된 부반송파수에서 송신된 BPSK 심볼 개수에 따른 PAPR 성능을 나타낸 그래프이다.Figure 1 is a block diagram showing the configuration of a DFT-spread OFDM transmitter according to an embodiment of the present invention.
FIG. 2 is a block diagram showing the constellation rotation unit of FIG. 1 in detail.
FIG. 3 is a block diagram showing the pruned DFT diffusion unit of FIG. 1 in detail.
FIG. 4 is a detailed block diagram of the frequency domain spectrum shaping unit of FIG. 1.
Figure 5 is a flowchart of a DFT-spread OFDM transmission method according to an embodiment of the present invention.
Figure 6 is a block diagram showing the configuration of a DFT-spread OFDM receiver according to an embodiment of the present invention.
Figure 7 is a flowchart of a DFT-spread OFDM reception method according to an embodiment of the present invention.
Figure 8 is a graph showing frequency efficiency according to the number of BPSK symbols transmitted on a fixed subcarrier.
Figure 9 is a graph showing PAPR performance according to the number of BPSK symbols transmitted on a fixed subcarrier number.

본 발명은 다양한 변경을 가할 수 있고 여러 가지 실시예를 가질 수 있는바, 특정 실시예들을 도면에 예시하고 상세하게 설명하고자 한다.Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail.

그러나 이는 본 발명을 특정한 실시 형태에 대해 한정하려는 것이 아니며, 본 발명의 사상 및 기술범위에 포함되는 모든 변경, 균등물 내지 대체물을 포함하는 것으로 이해되어야 한다.However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

제1, 제2 등의 용어는 다양한 구성요소들을 설명하는 데 사용될 수 있지만, 상기 구성요소들은 상기 용어들에 의해 한정되어서는 안 된다. 상기 용어들은 하나의 구성요소를 다른 구성요소로부터 구별하는 목적으로만 사용된다. 예를 들어, 본 발명의 권리범위를 벗어나지 않으면서 제1 구성요소는 제2 구성요소로 명명될 수 있고, 유사하게 제2 구성요소도 제1 구성요소로 명명될 수 있다.Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component without departing from the scope of the present invention, and similarly, the second component may also be named a first component.

어떤 구성요소가 다른 구성요소에 "연결되어" 있다거나 "접속되어" 있다고 언급된 때에는 그 다른 구성요소에 직접적으로 연결되어 있거나 또는 접속되어 있을 수도 있지만, 중간에 다른 구성요소가 존재할 수도 있다고 이해되어야 할 것이다. 반면에, 어떤 구성요소가 다른 구성요소에 "직접 연결되어" 있다거나 "직접 접속되어" 있다고 언급된 때에는 중간에 다른 구성요소가 존재하지 않는 것으로 이해되어야 할 것이다.When a component is said to be “connected” or “connected” to another component, it should be understood that it may be directly connected or connected to the other component, but that other components may exist in between. something to do. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

본 출원에서 사용한 용어는 단지 특정한 실시예를 설명하기 위해 사용된 것으로, 본 발명을 한정하려는 의도가 아니다. 단수의 표현은 문맥상 명백하게 다르게 뜻하지 않는 한 복수의 표현을 포함한다. 본 출원에서, "포함하다" 또는 "가지다" 등의 용어는 명세서상에 기재된 특징, 숫자, 단계, 동작, 구성요소, 부품 또는 이들을 조합한 것이 존재함을 지정하려는 것이지, 하나 또는 그 이상의 다른 특징들이나 숫자, 단계, 동작, 구성요소, 부품 또는 이들을 조합한 것들의 존재 또는 부가 가능성을 미리 배제하지 않는 것으로 이해되어야 한다.The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

다르게 정의되지 않는 한, 기술적이거나 과학적인 용어를 포함해서 여기서 사용되는 모든 용어들은 본 발명이 속하는 기술분야에서 통상의 지식을 가진 자에 의해 일반적으로 이해되는 것과 동일한 의미를 가지고 있다. 일반적으로 사용되는 사전에 정의되어 있는 것과 같은 용어들은 관련 기술의 문맥상 가지는 의미와 일치하는 의미를 가진 것으로 해석되어야 하며, 본 출원에서 명백하게 정의하지 않는 한 이상적이거나 과도하게 형식적인 의미로 해석되지 않는다.Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as having an ideal or excessively formal meaning unless clearly defined in the present application. .

이하에서는 첨부된 도면을 참조하여 본 발명의 바람직한 실시예를 본 발명이 속하는 기술분야에서 통상의 지식을 가진 사람이 본 발명을 쉽게 실시할 수 있도록 명확하고 상세하게 설명하기로 한다.Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described clearly and in detail so that a person skilled in the art can easily practice the present invention.

도 1은 본 발명의 일 실시예에 따른 DFT-spread OFDM 송신기의 구성을 나타낸 블록도이고, 도 2는 도 1의 성상 회전부를 상세하게 나타낸 블록도이고, 도 3은 도 1의 pruned DFT 확산부를 상세하게 나타낸 블록도이고, 도 4는 도 1의 주파수 영역 스펙트럼 성형부를 상세하게 블록도이다.FIG. 1 is a block diagram showing the configuration of a DFT-spread OFDM transmitter according to an embodiment of the present invention, FIG. 2 is a block diagram showing the constellation rotation unit of FIG. 1 in detail, and FIG. 3 is a pruned DFT spread unit of FIG. 1. It is a detailed block diagram, and FIG. 4 is a detailed block diagram of the frequency domain spectrum shaping unit of FIG. 1.

도 1을 참조하면, 본 발명의 일 실시예에 따른 DFT-spread OFDM 송신기(100)는 성상 회전부(110), pruned DFT 확산부(120), 주파수 영역 스펙트럼 성형부(130), 부반송파 할당부(140) 및 신호 생성부(150)를 포함할 수 있다. 신호 생성부(150)는 N-포인트 IDFT부(151) 및 순환 전치 삽입부(153)를 포함할 수 있다.Referring to Figure 1, the DFT-spread OFDM transmitter 100 according to an embodiment of the present invention includes a constellation rotation unit 110, a pruned DFT spreading unit 120, a frequency domain spectrum shaping unit 130, and a subcarrier allocation unit ( 140) and a signal generator 150. The signal generation unit 150 may include an N-point IDFT unit 151 and a cyclic prefix insertion unit 153.

성상 회전부(110)는 M개의 PAM 심볼을 포함하는 심볼벡터(

Figure 112021101498369-pat00052
)를 성상 회전각(
Figure 112021101498369-pat00053
)만큼 성상 회전시켜 성상 회전된 심볼벡터(
Figure 112021101498369-pat00054
)를 생성한다. 도 2에 도시된 바와 같이, 성상 회전된 심볼벡터(
Figure 112021101498369-pat00055
)는
Figure 112021101498369-pat00056
에 의해 생성될 수 있으며, 대각행렬
Figure 112021101498369-pat00057
은 수학식 1에 의해 정의될 수 있다.The constellation rotation unit 110 is a symbol vector containing M PAM symbols (
Figure 112021101498369-pat00052
) as the rotation angle (
Figure 112021101498369-pat00053
) by rotating the constellation and creating the rotated symbol vector (
Figure 112021101498369-pat00054
) is created. As shown in Figure 2, the constellation rotated symbol vector (
Figure 112021101498369-pat00055
)Is
Figure 112021101498369-pat00056
Can be generated by, diagonal matrix
Figure 112021101498369-pat00057
Can be defined by Equation 1.

성상 회전각(

Figure 112021101498369-pat00059
)은 심볼벡터(
Figure 112021101498369-pat00060
)의 길이 M과 할당된 부반송파의 개수 L에 따라 결정될 수 있다. 구체적으로, 성상 회전각(
Figure 112021101498369-pat00061
)은 M이 짝수인 경우 수학식 2에 의해 결정될 수 있고, M이 홀수인 경우 수학식 3에 의해 결정될 수 있다.Constellation rotation angle (
Figure 112021101498369-pat00059
) is the symbol vector (
Figure 112021101498369-pat00060
) can be determined according to the length M and the number of allocated subcarriers L. Specifically, the constellation rotation angle (
Figure 112021101498369-pat00061
) can be determined by Equation 2 when M is an even number, and can be determined by Equation 3 when M is an odd number.

수학식 2 및 수학식 3에서,

Figure 112021101498369-pat00064
는 나머지(modulo) 연산이다.In Equation 2 and Equation 3,
Figure 112021101498369-pat00064
is a modulo operation.

pruned DFT 확산부(120)는 pruned DFT 행렬(

Figure 112021101498369-pat00065
)을 이용하여 상기 성상 회전된 심볼벡터(
Figure 112021101498369-pat00066
)를 확산시켜 pruned DFT 확산된 벡터(
Figure 112021101498369-pat00067
)를 생성한다. 도 3에 도시된 바와 같이, pruned DFT 확산된 벡터(
Figure 112021101498369-pat00068
)는
Figure 112021101498369-pat00069
에 의해 생성될 수 있으며, 이때 pruned DFT 행렬(
Figure 112021101498369-pat00070
)은 M-포인트 DFT 행렬(
Figure 112021101498369-pat00071
)에서 마지막 (M-L)개의 행을 제거한 L×M 크기의 행렬이다. pruned DFT 행렬(
Figure 112021101498369-pat00072
)의 (i, j) 성분은 수학식 4에 의해 결정될 수 있다.The pruned DFT diffusion unit 120 is a pruned DFT matrix (
Figure 112021101498369-pat00065
) using the constellation rotated symbol vector (
Figure 112021101498369-pat00066
) by spreading the pruned DFT spread vector (
Figure 112021101498369-pat00067
) is created. As shown in Figure 3, the pruned DFT spread vector (
Figure 112021101498369-pat00068
)Is
Figure 112021101498369-pat00069
It can be generated by , where the pruned DFT matrix (
Figure 112021101498369-pat00070
) is the M-point DFT matrix (
Figure 112021101498369-pat00071
) is a matrix of size L×M in which the last (ML) rows have been removed. pruned DFT matrix (
Figure 112021101498369-pat00072
) The (i, j) components of ) can be determined by Equation 4.

수학식 4에서, 인덱스 i, j는 각각 1≤i≤L, 1≤j≤M 을 만족한다.In Equation 4, indices i and j satisfy 1≤i≤L and 1≤j≤M, respectively.

주파수 영역 스펙트럼 성형부(130)는 상기 pruned DFT 확산된 벡터(

Figure 112021101498369-pat00074
)에 성형벡터(
Figure 112021101498369-pat00075
)를 하다마드 곱(Hadamard product)함으로써 주파수 영역 스펙트럼 성형된 벡터(
Figure 112021101498369-pat00076
)를 생성한다. 또는, 도 4에 도시된 바와 같이, 주파수 영역 스펙트럼 성형된 벡터(
Figure 112021101498369-pat00077
)는 상기 pruned DFT 확산된 벡터(
Figure 112021101498369-pat00078
)에 성형벡터(
Figure 112021101498369-pat00079
)를 대각요소로 가지는 행렬(
Figure 112021101498369-pat00080
)을 곱함으로써 생성될 수도 있다. L×1 크기의 성형벡터(
Figure 112021101498369-pat00081
)는 수학식 5에 의해 정의될 수 있다.The frequency domain spectrum shaping unit 130 is the pruned DFT spread vector (
Figure 112021101498369-pat00074
) to the forming vector (
Figure 112021101498369-pat00075
) by the Hadamard product to obtain a frequency domain spectrum shaped vector (
Figure 112021101498369-pat00076
) is created. Alternatively, as shown in Figure 4, the frequency domain spectrally shaped vector (
Figure 112021101498369-pat00077
) is the pruned DFT spread vector (
Figure 112021101498369-pat00078
) to the forming vector (
Figure 112021101498369-pat00079
) as the diagonal elements (
Figure 112021101498369-pat00080
) can also be created by multiplying. A shaping vector of size L×1 (
Figure 112021101498369-pat00081
) can be defined by Equation 5.

성형벡터(

Figure 112021101498369-pat00083
)의 각각의 성분은 심볼벡터(
Figure 112021101498369-pat00084
)의 길이 M과 할당된 부반송파의 개수 L에 따라 결정될 수 있다. 구체적으로, 상기 성형벡터(
Figure 112021101498369-pat00085
)의 l번째 성분은 M이 짝수인 경우 수학식 6에 의해 결정될 수 있고, M이 홀수인 경우 수학식 7에 의해 결정될 수 있다.Molding vector (
Figure 112021101498369-pat00083
) Each component is a symbol vector (
Figure 112021101498369-pat00084
) can be determined according to the length M and the number of allocated subcarriers L. Specifically, the forming vector (
Figure 112021101498369-pat00085
) can be determined by Equation 6 when M is an even number, and can be determined by Equation 7 when M is an odd number.

수학식 6 및 수학식 7에서, l = 0, 1, 2, …, L-1 이고, M/2≤L≤M 을 만족한다.In Equation 6 and Equation 7, l = 0, 1, 2, … , L-1, and satisfies M/2≤L≤M.

부반송파 할당부(140)는 상기 주파수 영역 스펙트럼 성형된 벡터(

Figure 112021101498369-pat00088
)를 할당된 주파수 범위의 부반송파에 할당한다. 주파수 영역 스펙트럼 성형된 벡터(
Figure 112021101498369-pat00089
)가 부반송파에 할당되면 N-포인트 IDFT부(151) 및 순환 전치 삽입부(153)를 거쳐 DFT-spread OFDM 신호(
Figure 112021101498369-pat00090
)가 생성된다. N-포인트 IDFT부(151) 및 순환 전치 삽입부(153)의 동작은 본 발명이 속하는 기술분야에서 널리 알려진 기술이므로 본 명세서에서는 그 설명을 생략하기로 한다.The subcarrier allocation unit 140 is configured to form the frequency domain spectrum vector (
Figure 112021101498369-pat00088
) is assigned to the subcarriers in the assigned frequency range. Frequency domain spectrally shaped vector (
Figure 112021101498369-pat00089
) is assigned to the subcarrier, it passes through the N-point IDFT unit 151 and the cyclic prefix insertion unit 153 to provide a DFT-spread OFDM signal (
Figure 112021101498369-pat00090
) is created. Since the operations of the N-point IDFT unit 151 and the cyclic prefix insertion unit 153 are widely known in the technical field to which the present invention pertains, their description will be omitted in this specification.

도 5는 본 발명의 일 실시예에 따른 DFT-spread OFDM 송신 방법의 순서도이다.Figure 5 is a flowchart of a DFT-spread OFDM transmission method according to an embodiment of the present invention.

본 발명의 일 실시예에 따른 DFT-spread OFDM 송신 방법은 도 1의 DFT-spread OFDM 송신기(100)에 의해 수행될 수 있다.The DFT-spread OFDM transmission method according to an embodiment of the present invention can be performed by the DFT-spread OFDM transmitter 100 of FIG. 1.

도 5를 참조하면, 단계 S510에서는, M개의 PAM 심볼을 포함하는 심볼벡터(

Figure 112021101498369-pat00091
)를 성상 회전각(
Figure 112021101498369-pat00092
)만큼 성상 회전시켜 성상 회전된 심볼벡터(
Figure 112021101498369-pat00093
)를 생성한다. 이때 성상 회전각(
Figure 112021101498369-pat00094
)은 M이 짝수인 경우 수학식 2에 의해 결정될 수 있고, M이 홀수인 경우 수학식 3에 의해 결정될 수 있다.Referring to FIG. 5, in step S510, a symbol vector containing M PAM symbols (
Figure 112021101498369-pat00091
) as the rotation angle (
Figure 112021101498369-pat00092
) by rotating the constellation and creating the rotated symbol vector (
Figure 112021101498369-pat00093
) is created. At this time, the constellation rotation angle (
Figure 112021101498369-pat00094
) can be determined by Equation 2 when M is an even number, and can be determined by Equation 3 when M is an odd number.

단계 S520에서는, pruned DFT 행렬(

Figure 112021101498369-pat00095
)을 이용하여 상기 성상 회전된 심볼벡터(
Figure 112021101498369-pat00096
)를 확산시켜 pruned DFT 확산된 벡터(
Figure 112021101498369-pat00097
)를 생성한다. 이때 pruned DFT 행렬(
Figure 112021101498369-pat00098
)의 (i, j) 성분은 수학식 4에 의해 결정될 수 있다.In step S520, the pruned DFT matrix (
Figure 112021101498369-pat00095
) using the constellation rotated symbol vector (
Figure 112021101498369-pat00096
) by spreading the pruned DFT spread vector (
Figure 112021101498369-pat00097
) is created. At this time, the pruned DFT matrix (
Figure 112021101498369-pat00098
) The (i, j) components of ) can be determined by Equation 4.

단계 S530에서는, 상기 pruned DFT 확산된 벡터(

Figure 112021101498369-pat00099
)에 성형벡터(
Figure 112021101498369-pat00100
)를 하다마드 곱함으로써 주파수 영역 스펙트럼 성형된 벡터(
Figure 112021101498369-pat00101
)를 생성한다. 이때 상기 성형벡터(
Figure 112021101498369-pat00102
)의 l번째 성분은 M이 짝수인 경우 수학식 6에 의해 결정될 수 있고, M이 홀수인 경우 수학식 7에 의해 결정될 수 있다.In step S530, the pruned DFT spread vector (
Figure 112021101498369-pat00099
) to the forming vector (
Figure 112021101498369-pat00100
) by Hadamard multiplying the frequency domain spectrally shaped vector (
Figure 112021101498369-pat00101
) is created. At this time, the forming vector (
Figure 112021101498369-pat00102
) can be determined by Equation 6 when M is an even number, and can be determined by Equation 7 when M is an odd number.

단계 S540에서는, 상기 주파수 영역 스펙트럼 성형된 벡터(

Figure 112021101498369-pat00103
)를 할당된 주파수 범위의 부반송파에 할당한다.In step S540, the frequency domain spectrally shaped vector (
Figure 112021101498369-pat00103
) is assigned to the subcarriers in the assigned frequency range.

단계 S550에서는, 주파수 영역 스펙트럼 성형된 벡터(

Figure 112021101498369-pat00104
)가 부반송파에 할당되면 N-포인트 IDFT를 수행하고, 순환 전치를 삽입함으로써 신호를 생성한다.In step S550, the frequency domain spectrally shaped vector (
Figure 112021101498369-pat00104
) is assigned to a subcarrier, an N-point IDFT is performed and a signal is generated by inserting a cyclic prefix.

도 6은 본 발명의 일 실시예에 따른 DFT-spread OFDM 수신기의 구성을 나타낸 블록도이다.Figure 6 is a block diagram showing the configuration of a DFT-spread OFDM receiver according to an embodiment of the present invention.

도 6을 참조하면, 본 발명의 일 실시예에 따른 DFT-spread OFDM 수신기(600)는 순환 전치 제거부(610), N-포인트 DFT부(620), 주파수 영역 수신 스펙트럼 성형부(630), pruned IDFT부(640), 역성상 회전부(650) 및 추정부(660)를 포함할 수 있다.Referring to FIG. 6, the DFT-spread OFDM receiver 600 according to an embodiment of the present invention includes a cyclic prefix removal unit 610, an N-point DFT unit 620, a frequency domain reception spectrum shaping unit 630, It may include a pruned IDFT unit 640, an inverse constellation rotation unit 650, and an estimation unit 660.

순환 전치 제거부(610)는 채널을 통과한 신호(

Figure 112021101498369-pat00105
)를 수신하고, 상기 신호(
Figure 112021101498369-pat00106
)로부터 순환 전치를 제거함으로써 순환 전치가 제거된 벡터(
Figure 112021101498369-pat00107
)를 생성한다.The cyclic prefix removal unit 610 is a signal passing through the channel (
Figure 112021101498369-pat00105
), and receives the signal (
Figure 112021101498369-pat00106
) by removing the cyclic transpose from the vector (
Figure 112021101498369-pat00107
) is created.

N-포인트 DFT부(620)는 상기 순환 전치가 제거된 벡터(

Figure 112021101498369-pat00108
)에 N-포인트 DFT 를 수행한 후 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 벡터(
Figure 112021101498369-pat00109
)를 생성한다. 도 6에서는 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 벡터(
Figure 112021101498369-pat00110
)가 첫 L개의 부반송파에 해당되는 것으로 도시되어 있으나, 본 발명은 이에 제한되지 않는다. 이하에서 첫 L개의 부반송파에 할당되었을 경우를 가정하면 벡터(
Figure 112021101498369-pat00111
)는 수학식 8에 의해 정의될 수 있다.The N-point DFT unit 620 is a vector from which the cyclic transpose has been removed (
Figure 112021101498369-pat00108
After performing N-point DFT on ), the part corresponding to the subcarrier in the assigned frequency range was cut out (
Figure 112021101498369-pat00109
) is created. In Figure 6, the part corresponding to the subcarrier of the allocated frequency range is cut out (
Figure 112021101498369-pat00110
) is shown as corresponding to the first L subcarriers, but the present invention is not limited thereto. Hereinafter, assuming that it is assigned to the first L subcarriers, the vector (
Figure 112021101498369-pat00111
) can be defined by Equation 8.

여기서,

Figure 112021101498369-pat00113
은 L×L 단위 행렬이며
Figure 112021101498369-pat00114
은 L×(N-L) 영행렬이다.here,
Figure 112021101498369-pat00113
is the L×L identity matrix,
Figure 112021101498369-pat00114
is the L×(NL) zero matrix.

주파수 영역 수신 스펙트럼 성형부(630)는 상기 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 벡터(

Figure 112021101498369-pat00115
)에 수신 성형벡터(
Figure 112021101498369-pat00116
)의 켤레 복소 벡터를 하다마드 곱함으로써 주파수 영역 수신 스펙트럼 성형된 벡터를 생성한다.The frequency domain reception spectrum shaping unit 630 is a vector (
Figure 112021101498369-pat00115
) to the receiving shaping vector (
Figure 112021101498369-pat00116
) generates a frequency domain received spectrum shaped vector by Hadamard multiplying the complex conjugate vector of ).

Pruned IDFT부(640)는 상기 주파수 영역 수신 스펙트럼 성형된 벡터에 전치된 pruned DFT 행렬(

Figure 112021101498369-pat00117
)을 곱함으로써 역확산된 벡터를 생성한다.The pruned IDFT unit 640 is a pruned DFT matrix transposed to the frequency domain reception spectrum shaped vector (
Figure 112021101498369-pat00117
) to create a despread vector.

역성상 회전부(650)는 상기 역확산된 벡터를 역성상 회전각(

Figure 112021101498369-pat00118
)만큼 역성상 회전시켜 역성상 회전된 벡터를 생성한다.The inverse constellation rotation unit 650 converts the inverse constellation rotation angle (
Figure 112021101498369-pat00118
) to generate an inversely rotated vector.

추정부(660)는 상기 역성상 회전된 벡터의 실수부를 취함으로써 전송된 PAM 심볼 벡터의 추정값(

Figure 112021101498369-pat00119
)을 생성한다. 따라서, PAM 심볼 벡터의 추정값(
Figure 112021101498369-pat00120
)은 수학식 9와 같이 표현될 수 있다.The estimation unit 660 receives an estimated value of the transmitted PAM symbol vector by taking the real part of the inverse constellation rotated vector (
Figure 112021101498369-pat00119
) is created. Therefore, the estimate of the PAM symbol vector (
Figure 112021101498369-pat00120
) can be expressed as Equation 9.

여기서,

Figure 112021101498369-pat00122
은 L×1 수신 성형벡터이고, 윗첨자 *는 켤레 복소 벡터로의 변환을 의미하며, 역성상 회전각(
Figure 112021101498369-pat00123
)은 송신 회전각의 음수이다.here,
Figure 112021101498369-pat00122
is the L
Figure 112021101498369-pat00123
) is the negative of the transmission rotation angle.

PAM 심볼 벡터의 추정값(

Figure 112021101498369-pat00124
)은 L×1 주파수 영역 채널 대각 행렬(
Figure 112021101498369-pat00125
)을 사용하여 수학식 10과 같이 표현될 수 있다.Estimate of PAM symbol vector (
Figure 112021101498369-pat00124
) is the L×1 frequency domain channel diagonal matrix (
Figure 112021101498369-pat00125
) can be expressed as Equation 10.

여기서, 주파수 영역 채널 대각 행렬(

Figure 112021101498369-pat00127
)은 N×N 채널 대각 행렬(
Figure 112021101498369-pat00128
)을 사용하여 수학식 11과 같이 표현될 수 있다.Here, the frequency domain channel diagonal matrix (
Figure 112021101498369-pat00127
) is the N×N channel diagonal matrix (
Figure 112021101498369-pat00128
) can be expressed as Equation 11.

한편, 채널이 주파수 비선택적(frequency flat)인 경우 수신 성형벡터(

Figure 112021101498369-pat00130
)는 송신 성형벡터와 동일하게 선택될 수 있다.On the other hand, if the channel is frequency non-selective (frequency flat), the reception shaping vector (
Figure 112021101498369-pat00130
) can be selected the same as the transmission shaping vector.

도 7은 본 발명의 일 실시예에 따른 DFT-spread OFDM 수신 방법의 순서도이다.Figure 7 is a flowchart of a DFT-spread OFDM reception method according to an embodiment of the present invention.

본 발명의 일 실시예에 따른 DFT-spread OFDM 수신 방법은 도 6의 DFT-spread OFDM 수신기(600)에 의해 수행될 수 있다.The DFT-spread OFDM reception method according to an embodiment of the present invention can be performed by the DFT-spread OFDM receiver 600 of FIG. 6.

도 7을 참조하면, 단계 S710에서는, 채널을 통과한 신호(

Figure 112021101498369-pat00131
)를 수신하고, 상기 신호(
Figure 112021101498369-pat00132
)로부터 순환 전치를 제거함으로써 순환 전치가 제거된 벡터(
Figure 112021101498369-pat00133
)를 생성한다.Referring to FIG. 7, in step S710, a signal passing through the channel (
Figure 112021101498369-pat00131
), and receives the signal (
Figure 112021101498369-pat00132
) by removing the cyclic transpose from the vector (
Figure 112021101498369-pat00133
) is created.

단계 S720에서는, 상기 순환 전치가 제거된 벡터(

Figure 112021101498369-pat00134
)에 N-포인트 DFT를 수행한 후 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 벡터(
Figure 112021101498369-pat00135
)를 생성한다. 첫 L개의 부반송파에 할당되었을 경우 벡터(
Figure 112021101498369-pat00136
)는 수학식 8에 의해 정의될 수 있다.In step S720, the vector from which the cyclic transpose has been removed (
Figure 112021101498369-pat00134
After performing N-point DFT on ), the part corresponding to the subcarrier in the assigned frequency range was cut out (
Figure 112021101498369-pat00135
) is created. When assigned to the first L subcarriers, the vector (
Figure 112021101498369-pat00136
) can be defined by Equation 8.

단계 S730에서는, 상기 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 벡터(

Figure 112021101498369-pat00137
)에 수신 성형벡터(
Figure 112021101498369-pat00138
)의 켤레 복소 벡터를 하다마드 곱함으로써 주파수 영역 수신 스펙트럼 성형된 벡터를 생성한다.In step S730, a vector (
Figure 112021101498369-pat00137
) to the receiving shaping vector (
Figure 112021101498369-pat00138
) generates a frequency domain received spectrum shaped vector by Hadamard multiplying the complex conjugate vector of ).

채널이 주파수 비선택적인 경우 수신 성형벡터(

Figure 112021101498369-pat00139
)는 송신 성형벡터와 동일하게 선택될 수 있다.If the channel is frequency non-selective, the reception shaping vector (
Figure 112021101498369-pat00139
) can be selected the same as the transmission shaping vector.

단계 S740에서는, 상기 주파수 영역 수신 스펙트럼 성형된 벡터에 전치된 pruned DFT 행렬(

Figure 112021101498369-pat00140
)을 곱함으로써 역확산된 벡터를 생성한다.In step S740, the pruned DFT matrix (
Figure 112021101498369-pat00140
) to create a despread vector.

단계 S750에서는, 상기 역확산된 벡터를 역성상 회전각(

Figure 112021101498369-pat00141
)만큼 역성상 회전시켜 역성상 회전된 벡터를 생성한다.In step S750, the despreaded vector is converted into an inverse constellation rotation angle (
Figure 112021101498369-pat00141
) to generate an inversely rotated vector.

단계 S760에서는, 상기 역성상 회전된 벡터의 실수부를 취함으로써 전송된 PAM심볼 벡터의 추정값(

Figure 112021101498369-pat00142
)을 생성한다. PAM 심볼 벡터의 추정값(
Figure 112021101498369-pat00143
)은 수학식 9와 같이 표현될 수 있다.In step S760, the estimated value of the transmitted PAM symbol vector by taking the real part of the inverse constellation rotated vector (
Figure 112021101498369-pat00142
) is created. Estimate of PAM symbol vector (
Figure 112021101498369-pat00143
) can be expressed as Equation 9.

도 8은 고정된 부반송파수에서 송신된 BPSK 심볼 개수에 따른 주파수 효율을 나타낸 그래프이다.Figure 8 is a graph showing frequency efficiency according to the number of BPSK symbols transmitted on a fixed subcarrier.

도 8은 부반송파를 L = 24개 할당할 때, 성상 회전된 BPSK 심볼 벡터의 길이가 M = 24~48로 바뀔 때의 주파수효율을 도시한다. 도 8에 따르면 M = 24일 때 본 발명의 실시예들에 따른 성상 회전각 및 성형벡터는 스펙트럼 성형을 하지 않은 경우와 같은 주파수 효율을 가지며, M을 48까지 증가시키면 스펙트럼 성형을 하지 않은 경우의 2배까지 주파수 효율을 향상시킨다.Figure 8 shows the frequency efficiency when allocating L = 24 subcarriers and changing the length of the constellation rotated BPSK symbol vector to M = 24 to 48. According to Figure 8, when M = 24, the constellation rotation angle and shaping vector according to the embodiments of the present invention have the same frequency efficiency as when spectral shaping is not performed, and when M is increased to 48, the constellation rotation angle and shaping vector according to the embodiments of the present invention are the same as when spectral shaping is not performed. Improves frequency efficiency by up to 2 times.

도 9는 고정된 부반송파수에서 송신된 BPSK 심볼 개수에 따른 PAPR 성능을 나타낸 그래프이다.Figure 9 is a graph showing PAPR performance according to the number of BPSK symbols transmitted on a fixed subcarrier number.

도 9는 부반송파를 L = 24개 할당 할 때, 성상 회전된 BPSK 심볼 벡터의 길이가 M = 24~48로 바뀔 때의 PAPR값을 도시한다. 도 9에 따르면 M = 24일 때 본 발명의 실시예들에 따른 성상 회전각 및 성형벡터는 스펙트럼 성형을 하지 않은 경우에 비해 매우 낮은 PAPR 성능을 가지며, 특히 24 < M ≤ 44일 때 본 발명의 실시예들에 따른 성상 회전각 및 성형벡터는 낮은 PAPR 성능을 가지면서도 스펙트럼 성형을 하지 않은 경우에 비해 더 좋은 주파수 효율을 가진다. 비록 44 < M ≤ 48 은 기존의 pi/2-BPSK 심볼에 비해 비슷하거나 높은 PAPR 성능을 가지지만 더 높은 주파수 효율을 가진다. 따라서, 본 발명의 실시예들에 따른 성상 회전각 및 성형벡터를 사용하면 손쉽게 PAPR 성능과 주파수효율을 트레이드-오프(trade-off) 할 수 있다.Figure 9 shows the PAPR value when the length of the constellation rotated BPSK symbol vector changes to M = 24 to 48 when assigning L = 24 subcarriers. According to Figure 9, when M = 24, the constellation rotation angle and shaping vector according to the embodiments of the present invention have very low PAPR performance compared to the case without spectral shaping, especially when 24 < M ≤ 44. The constellation rotation angle and shaping vector according to the embodiments have low PAPR performance and have better frequency efficiency compared to the case without spectral shaping. Although 44 < M ≤ 48 has similar or higher PAPR performance than the existing pi/2-BPSK symbol, it has higher frequency efficiency. Therefore, by using the constellation rotation angle and shaping vector according to the embodiments of the present invention, it is possible to easily trade-off PAPR performance and frequency efficiency.

이상에서 도면 및 실시예를 참조하여 설명하였지만, 본 발명의 보호범위가 상기 도면 또는 실시예에 의해 한정되는 것을 의미하지는 않으며 해당 기술 분야의 숙련된 당업자는 하기의 청구범위에 기재된 본 발명의 사상 및 영역으로부터 벗어나지 않는 범위 내에서 본 발명을 다양하게 수정 및 변경시킬 수 있음을 이해할 수 있을 것이다.Although it has been described above with reference to the drawings and examples, it does not mean that the scope of protection of the present invention is limited by the drawings or examples, and those skilled in the art will understand the spirit and scope of the present invention as set forth in the following claims. It will be understood that various modifications and changes can be made to the present invention without departing from the scope.

100: DFT-spread OFDM 송신기
110: 성상 회전부
120: pruned DFT 확산부
130: 주파수 영역 스펙트럼 성형부
140: 부반송파 할당부
150: 신호 생성부
151: N-포인트 IDFT부
153: 순환 전치 삽입부
600: DFT-spread OFDM 수신기
610: 순환 전치 제거부
620: N-포인트 DFT부
630: 주파수 영역 수신 스펙트럼 성형부
640: pruned IDFT부
650: 역성상 회전부
660: 추정부100: DFT-spread OFDM transmitter
110: Constellation rotation part
120: pruned DFT diffusion section
130: Frequency domain spectrum shaping unit
140: Subcarrier allocation unit
150: signal generation unit
151: N-point IDFT section
153: circular anterior teeth insertion part
600: DFT-spread OFDM receiver
610: circular anterior teeth removal unit
620: N-point DFT unit
630: Frequency domain reception spectrum shaping unit
640: pruned IDFT section
650: Inverse rotation part
660: Estimation Department

Claims (11)

이산푸리에변환(DFT: discrete Fourier transform)-확산(spread) 직교주파수분할다중화(OFDM: orthogonal frequency-division multiplexing) 송신기에 있어서,
M개의 PAM(pulse amplitude modulation) 심볼을 포함하는 심볼벡터(
Figure 112023058964854-pat00144
)를 성상 회전각(
Figure 112023058964854-pat00145
)만큼 성상 회전시켜 M*1 크기의 성상 회전된 심볼벡터(
Figure 112023058964854-pat00146
)를 생성하는 성상 회전부;
pruned DFT 행렬(
Figure 112023058964854-pat00147
)을 이용하여 상기 성상 회전된 심볼벡터(
Figure 112023058964854-pat00148
)를 확산시켜 L*1 크기의 pruned DFT 확산된 벡터(
Figure 112023058964854-pat00149
)를 생성하며, 상기 L은 할당된 주파수 범위의 부반송파의 개수로 상기 M보다 작은, pruned DFT 확산부;
상기 pruned DFT 확산된 벡터(
Figure 112023058964854-pat00150
)에 성형벡터(
Figure 112023058964854-pat00151
)를 하다마드 곱(Hadamard product)함으로써 주파수 영역 스펙트럼 성형된 벡터(
Figure 112023058964854-pat00152
)를 생성하는 주파수 영역 스펙트럼 성형부; 및
상기 주파수 영역 스펙트럼 성형된 벡터(
Figure 112023058964854-pat00153
)를 상기 부반송파에 할당하는 부반송파할당부;를 포함하고,
상기 성형벡터()는 상기 M 및 상기 L에 따라 결정되고,
상기 M이 홀수인 경우, 상기 성상 회전각()은 하기의 수학식 에 의해 결정되고, 상기 성형벡터()의 l번째 성분은 하기의 수학식
에 의해 결정되는 - 여기서, l = 0, 1, 2, …, L-1 이고, M/2≤L≤M 임 -, DFT-spread OFDM 송신기.In a discrete Fourier transform (DFT)-spread orthogonal frequency-division multiplexing (OFDM) transmitter,
A symbol vector containing M PAM (pulse amplitude modulation) symbols (
Figure 112023058964854-pat00144
) as the rotation angle (
Figure 112023058964854-pat00145
) by rotating the constellation to create a constellation of M*1 size and the rotated symbol vector (
Figure 112023058964854-pat00146
) A constellation rotating part that generates;
pruned DFT matrix (
Figure 112023058964854-pat00147
) using the constellation rotated symbol vector (
Figure 112023058964854-pat00148
) by spreading the pruned DFT spread vector of size L*1 (
Figure 112023058964854-pat00149
), where L is the number of subcarriers in the allocated frequency range and is smaller than the M, a pruned DFT spreader;
The pruned DFT spread vector (
Figure 112023058964854-pat00150
) to the forming vector (
Figure 112023058964854-pat00151
) by the Hadamard product to obtain a frequency domain spectrum shaped vector (
Figure 112023058964854-pat00152
) a frequency domain spectrum shaping unit that generates; and
The frequency domain spectrum is shaped by the vector (
Figure 112023058964854-pat00153
) includes a subcarrier allocation unit that allocates to the subcarrier,
The forming vector ( ) is determined according to the M and the L,
If M is an odd number, the constellation rotation angle ( ) is the equation below: It is determined by, and the forming vector ( )'s lth component is the equation below:
Determined by - where l = 0, 1, 2, … , L-1, and M/2≤L≤M -, DFT-spread OFDM transmitter. 제1항에 있어서,
상기 M이 짝수인 경우, 상기 성상 회전각(
Figure 112023058964854-pat00154
)은 하기의 수학식

에 의해 결정되는 - 여기서, L은 사용될 부반송파의 개수임 -, DFT-spread OFDM 송신기.According to paragraph 1,
If M is an even number, the constellation rotation angle (
Figure 112023058964854-pat00154
) is the equation below:

Determined by - where L is the number of subcarriers to be used -, DFT-spread OFDM transmitter. 삭제delete 제1항에 있어서,
상기 pruned DFT 행렬(
Figure 112021101498369-pat00158
)의 (i, j) 성분은 하기의 수학식

에 의해 결정되는 - 여기서, 인덱스 i, j는 각각 1≤i≤L, 1≤j≤L 을 만족함 -, DFT-spread OFDM 송신기.According to paragraph 1,
The pruned DFT matrix (
Figure 112021101498369-pat00158
) The (i, j) components of ) are expressed in the following equation:

determined by - where the indices i and j satisfy 1≤i≤L and 1≤j≤L, respectively-, DFT-spread OFDM transmitter. 제1항에 있어서,
상기 M이 짝수인 경우, 상기 성형벡터(
Figure 112023058964854-pat00160
)의 l번째 성분은 하기의 수학식

에 의해 결정되는 - 여기서, l = 0, 1, 2, …, L-1 이고, M/2≤L≤M 임 -, DFT-spread OFDM 송신기.According to paragraph 1,
If M is an even number, the shaping vector (
Figure 112023058964854-pat00160
)'s lth component is the equation below:

Determined by - where l = 0, 1, 2, … , L-1, and M/2≤L≤M -, DFT-spread OFDM transmitter. 삭제delete 제1항에 있어서,
상기 부반송파할당부의 출력에 대하여 N-포인트 IDFT(N-point inverse discrete Fourier transform)를 수행하고 순환전치(CP: cyclic prefix)를 삽입함으로써 신호(
Figure 112021101498369-pat00164
)를 생성하는 OFDM신호생성부를 더 포함하는, DFT-spread OFDM 송신기.According to paragraph 1,
By performing N-point inverse discrete Fourier transform (IDFT) on the output of the subcarrier allocation unit and inserting a cyclic prefix (CP), the signal (
Figure 112021101498369-pat00164
) A DFT-spread OFDM transmitter further comprising an OFDM signal generator that generates. 이산푸리에변환(DFT: discrete Fourier transform)-확산(spread) 직교주파수분할다중화(OFDM: orthogonal frequency-division multiplexing) 송신기에 의해 수행되는 DFT-spread OFDM 송신 방법에 있어서,
M개의 PAM(pulse amplitude modulation) 심볼을 포함하는 심볼벡터(
Figure 112023058964854-pat00165
)를 성상 회전각(
Figure 112023058964854-pat00166
)만큼 성상 회전시켜 M*1 크기의 성상 회전된 심볼벡터(
Figure 112023058964854-pat00167
)를 생성하는 단계;
pruned DFT 행렬(
Figure 112023058964854-pat00168
)을 이용하여 상기 성상 회전된 심볼벡터(
Figure 112023058964854-pat00169
)를 확산시켜 pruned DFT 확산된 벡터(
Figure 112023058964854-pat00170
)를 생성하며, 상기 L은 할당된 주파수 범위의 부반송파의 개수로 상기 M보다 작은, 단계;
상기 pruned DFT 확산된 벡터(
Figure 112023058964854-pat00171
)에 성형벡터(
Figure 112023058964854-pat00172
)를 하다마드 곱(Hadamard product)함으로써 주파수 영역 스펙트럼 성형된 벡터(
Figure 112023058964854-pat00173
)를 생성하는 단계; 및
상기 주파수 영역 스펙트럼 성형된 벡터(
Figure 112023058964854-pat00174
)를 상기 부반송파에 할당하는 단계;를 포함하고,
상기 성형벡터()는 상기 M 및 상기 L에 따라 결정되고,
상기 M이 홀수인 경우, 상기 성상 회전각()은 하기의 수학식 에 의해 결정되고, 상기 성형벡터()의 l번째 성분은 하기의 수학식 에 의해 결정되는 - 여기서, l = 0, 1, 2, …, L-1 이고, M/2≤L≤M 임 -, DFT-spread OFDM 송신 방법.In the DFT-spread OFDM transmission method performed by a discrete Fourier transform (DFT)-spread orthogonal frequency-division multiplexing (OFDM) transmitter,
A symbol vector containing M PAM (pulse amplitude modulation) symbols (
Figure 112023058964854-pat00165
) as the rotation angle (
Figure 112023058964854-pat00166
) by rotating the constellation to create a constellation of M*1 size and the rotated symbol vector (
Figure 112023058964854-pat00167
) generating;
pruned DFT matrix (
Figure 112023058964854-pat00168
) using the constellation rotated symbol vector (
Figure 112023058964854-pat00169
) by spreading the pruned DFT spread vector (
Figure 112023058964854-pat00170
), wherein L is the number of subcarriers in the allocated frequency range and is less than the M;
The pruned DFT spread vector (
Figure 112023058964854-pat00171
) to the forming vector (
Figure 112023058964854-pat00172
) by the Hadamard product to obtain a frequency domain spectrum shaped vector (
Figure 112023058964854-pat00173
) generating; and
The frequency domain spectrum is shaped by the vector (
Figure 112023058964854-pat00174
) allocating to the subcarrier; including,
The forming vector ( ) is determined according to the M and the L,
If M is an odd number, the constellation rotation angle ( ) is the equation below: It is determined by, and the forming vector ( )'s lth component is the equation below: Determined by - where l = 0, 1, 2, … , L-1, and M/2≤L≤M -, DFT-spread OFDM transmission method. 이산푸리에변환(DFT: discrete Fourier transform)-확산(spread) 직교주파수분할다중화(OFDM: orthogonal frequency-division multiplexing) 수신기에 있어서,
채널을 통과한 신호(
Figure 112023058964854-pat00175
)를 수신하고, 상기 신호(
Figure 112023058964854-pat00176
)로부터 순환 전치(CP: cyclic prefix)를 제거함으로써 순환 전치가 제거된 벡터(
Figure 112023058964854-pat00177
)를 생성하는 순환 전치 제거부;
상기 순환 전치가 제거된 벡터(
Figure 112023058964854-pat00178
)에 N-포인트 DFT(N-point discrete Fourier transform)를 수행한 후 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 L-1 크기의 벡터(
Figure 112023058964854-pat00179
)를 생성하며, 상기 L은 할당된 주파수 범위의 부반송파의 개수인, N-포인트 DFT 부;
상기 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 벡터(
Figure 112023058964854-pat00180
)에 수신 성형벡터(
Figure 112023058964854-pat00181
)의 켤레 복소 벡터를 하다마드 곱함으로써 주파수 영역 수신 스펙트럼 성형된 벡터를 생성하는 주파수 영역 수신 스펙트럼 성형부;
상기 주파수 영역 수신 스펙트럼 성형된 벡터에 전치된 pruned DFT 행렬(
Figure 112023058964854-pat00182
)을 곱함으로써 M*1 크기의 역확산된 벡터를 생성하며, 상기 M은 상기 수신기가 복원할 PAM 심볼의 개수이고 상기 L은 상기 M 보다 작은, pruned IDFT부;
상기 역확산된 벡터를 역성상 회전각(
Figure 112023058964854-pat00183
)만큼 역성상 회전시켜 역성상 회전된 벡터를 생성하는 역성상회전부; 및
상기 역성상 회전된 벡터의 실수부를 취함으로써 전송된 PAM(pulse amplitude modulation) 심볼 벡터의 추정값(
Figure 112023058964854-pat00184
)을 생성하는 추정부;를 포함하고,
상기 성형벡터()는 상기 M 및 상기 L에 따라 결정되고,
상기 M이 홀수인 경우 상기 역성상 회전각()는 하기의 수학식 에 의해 결정되고, 상기 성형벡터()의 l번째 성분은 하기의 수학식 에 의해 결정되는 - 여기서, l = 0, 1, 2, …, L-1 이고, M/2≤L≤M 임 -, DFT-spread OFDM 수신기.In a discrete Fourier transform (DFT)-spread orthogonal frequency-division multiplexing (OFDM) receiver,
The signal passing through the channel (
Figure 112023058964854-pat00175
), and receives the signal (
Figure 112023058964854-pat00176
) by removing the cyclic prefix (CP) from the vector (
Figure 112023058964854-pat00177
) Cyclic preposition removal unit that generates ;
The vector from which the cyclic transposition has been removed (
Figure 112023058964854-pat00178
After performing N-point DFT (N-point discrete Fourier transform) on ), the part corresponding to the subcarrier in the assigned frequency range was cut off to a vector of size L-1 (
Figure 112023058964854-pat00179
), where L is the number of subcarriers in the assigned frequency range, an N-point DFT unit;
A vector (
Figure 112023058964854-pat00180
) to the receiving shaping vector (
Figure 112023058964854-pat00181
a frequency domain reception spectrum shaping unit that generates a frequency domain reception spectrum shaping vector by Hadamard multiplying the conjugate complex vector of );
The pruned DFT matrix transposed to the frequency domain received spectrum shaped vector (
Figure 112023058964854-pat00182
) to generate a despread vector of size M*1, where M is the number of PAM symbols to be restored by the receiver, and L is smaller than M, a pruned IDFT unit;
The inverse constellation rotation angle (
Figure 112023058964854-pat00183
) an inverse constellation rotation unit that rotates the inverse constellation to generate an inverse constellation rotated vector; and
An estimate of the transmitted PAM (pulse amplitude modulation) symbol vector by taking the real part of the inverse constellation rotated vector (
Figure 112023058964854-pat00184
) and an estimation unit that generates,
The forming vector ( ) is determined according to the M and the L,
If M is an odd number, the inverse rotation angle ( ) is the equation below: It is determined by, and the forming vector ( )'s lth component is the equation below: Determined by - where l = 0, 1, 2, … , L-1, and M/2≤L≤M -, DFT-spread OFDM receiver. 제9항에 있어서,
상기 수신 성형벡터는 송신 성형벡터와 동일한, DFT-spread OFDM 수신기.According to clause 9,
A DFT-spread OFDM receiver in which the receiving shaping vector is the same as the transmitting shaping vector. 이산푸리에변환(DFT: discrete Fourier transform)-확산(spread) 직교주파수분할다중화(OFDM: orthogonal frequency-division multiplexing) 수신기에 의해 수행되는 DFT-spread OFDM 수신 방법에 있어서,
채널을 통과한 신호(
Figure 112023058964854-pat00185
)를 수신하고, 상기 신호(
Figure 112023058964854-pat00186
)로부터 순환 전치(CP: cyclic prefix)를 제거함으로써 순환 전치가 제거된 벡터(
Figure 112023058964854-pat00187
)를 생성하는 단계;
상기 순환 전치가 제거된 벡터(
Figure 112023058964854-pat00188
)에 N-포인트 DFT(N-point discrete Fourier transform)를 수행한 후 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 L*1 크기의 벡터(
Figure 112023058964854-pat00189
)를 생성하며, 상기 L은 할당된 주파수 범위의 부반송파의 개수인, 단계;
상기 할당된 주파수 범위의 부반송파에 해당하는 부분을 잘라낸 벡터(
Figure 112023058964854-pat00190
)에 수신 성형벡터(
Figure 112023058964854-pat00191
)의 켤레 복소 벡터를 하다마드 곱함으로써 주파수 영역 수신 스펙트럼 성형된 벡터를 생성하는 단계;
상기 주파수 영역 수신 스펙트럼 성형된 벡터에 전치된 pruned DFT 행렬(
Figure 112023058964854-pat00192
)을 곱함으로써 M*1 크기의 역확산된 벡터를 생성하며, 상기 M은 상기 수신기가 복원할 PAM 심볼의 개수이고, 상기 L은 상기 M보다 작은, 단계;
상기 역확산된 벡터를 역성상 회전각(
Figure 112023058964854-pat00193
)만큼 역성상 회전시켜 역성상 회전된 벡터를 생성하는 단계; 및
상기 역성상 회전된 벡터의 실수부를 취함으로써 전송된 PAM(pulse amplitude modulation) 심볼 벡터의 추정값(
Figure 112023058964854-pat00194
)을 생성하는 단계;를 포함하고,
상기 성형벡터()는 상기 M 및 상기 L에 따라 결정되고,
상기 M이 홀수인 경우 상기 역성상 회전각()는 하기의 수학식 에 의해 결정되고, 상기 성형벡터()의 l번째 성분은 하기의 수학식
에 의해 결정되는 - 여기서, l = 0, 1, 2, …, L-1 이고, M/2≤L≤M 임 -, DFT-spread OFDM 수신 방법.In the DFT-spread OFDM reception method performed by a discrete Fourier transform (DFT)-spread orthogonal frequency-division multiplexing (OFDM) receiver,
The signal passing through the channel (
Figure 112023058964854-pat00185
), and receives the signal (
Figure 112023058964854-pat00186
) by removing the cyclic prefix (CP) from the vector (
Figure 112023058964854-pat00187
) generating;
The vector from which the cyclic transposition has been removed (
Figure 112023058964854-pat00188
) after performing N-point DFT (N-point discrete Fourier transform) on the L*1-sized vector (
Figure 112023058964854-pat00189
), where L is the number of subcarriers in the assigned frequency range;
A vector (
Figure 112023058964854-pat00190
) to the receiving shaping vector (
Figure 112023058964854-pat00191
generating a frequency domain received spectrum shaped vector by Hadamard multiplying the complex conjugate vector of );
The pruned DFT matrix transposed to the frequency domain received spectrum shaped vector (
Figure 112023058964854-pat00192
) to generate a despread vector of size M*1, where M is the number of PAM symbols to be restored by the receiver, and L is smaller than M;
The inverse constellation rotation angle (
Figure 112023058964854-pat00193
) to generate an inverse-constellation rotated vector; and
An estimate of the transmitted PAM (pulse amplitude modulation) symbol vector by taking the real part of the inverse constellation rotated vector (
Figure 112023058964854-pat00194
), including generating;
The forming vector ( ) is determined according to the M and the L,
If M is an odd number, the inverse rotation angle ( ) is the equation below: It is determined by, and the forming vector ( )'s lth component is the equation below:
Determined by - where l = 0, 1, 2, … , L-1, and M/2≤L≤M -, DFT-spread OFDM reception method.
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